Stent/graft assembly

ABSTRACT

A stent/graft assembly includes a tubular graft connected in substantially end-to-end relationship with a generally tubular stent. Free ends of the stent and graft extend in opposite directions from the end-to-end connection during a pre-deployment orientation of the assembly. However, the graft is inverted during deployment so that free ends of the graft and the stent extend in substantially the same direction from the end-to-end connection in a post-deployment orientation. Thus, at least a portion of the stent is disposed within at least a portion of the graft in a post-deployment orientation of the assembly.

[0001] This application is a continuation-in-part of application Ser.No. 09/900,241, application Ser. No. 10/299,882 and application Ser. No.10/612,531 all of which are pending.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The subject invention relates to a stent and graft assembly fortreating vascular anomalies, such as aneurysms.

[0004] 2. Description of the Related Art

[0005] Vascular anomalies are considered to include blood vessels thatare damaged, weakened or otherwise impaired. The anomaly may include alocal change in the cross-sectional dimensions of the blood vessel. Forexample, aneurysms include a local area where a blood vessel expands toa larger cross-sectional area due to disease, weakening or other damage.

[0006] The aorta extends from the heart and through the abdomen. Theabdominal aorta then feeds abdominal organs and the right and left iliacarteries that bring blood to the right and left legs respectively. Theaorta is prone to aneurysms. Aortic aneurysms that are not treated in atimely manner can lead to rupture, occlusion, infection or theproduction of emboli which can flow downstream and occlude a smallerblood vessel. A ruptured aortic aneurysm typically is fatal due to aloss of the large volume of blood that flows through the abdominalaorta.

[0007] Aneurysms can be corrected by grafts. The typical graft isimplanted surgically by accessing the site of the aneurysm, cutting openthe aneurysm and then surgically forming an appropriate fabric into atubular shape that spans the aneurysm. Thus, upstream and downstreamends of the prior art graft are sutured to healthier regions of theblood vessel.

[0008] The prior art also includes endovascular grafts. An endovasculargraft comprises a flexible tubular member formed from a syntheticfabric. The graft is selected to have an outside cross-sectionaldimension that approximates the inside cross-sectional dimensions of theblood vessel on either side of the aneurysm. The graft also is selectedto have a length that exceeds the length of the damaged area of theblood vessel.

[0009] An unsupported flexible tubular graft has a tendency to collapsein the presence of the flowing blood and could be transported downstreamby the blood flow. As a result, endovascular grafts are used incombination with a stent. Stents take many forms, including balloonexpandable stents and self-expanding stents, but typically are resilientcylindrical members that are inserted axially through the tubular graftprior to insertion into the blood vessel. The stent and the graft aresutured together prior to deployment so that the opposed ends of thestent align with the opposed ends of the graft. The endovascular graftassembly then is inserted through a healthy region of the blood vesseland is advanced through the circulatory system to the aneurysm or otherdamaged region of the blood vessel. More particularly, the endovasculargraft assembly is advanced to a position where the endovascular graftassembly bridges the aneurysm or other damaged portion of the bloodvessel. However, the opposed axial ends of the endovascular graftassembly extend beyond the aneurysm. The stent then is expanded to holdthe graft in an expanded tubular condition with at least the opposedaxial end regions of the graft being urged tightly against the interiorof healthy regions of the blood vessel. The stent and the graft of theprior art endovascular graft assembly are coaxial, and longitudinallycoextensive.

[0010] Prior art assemblies of stents and grafts typically perform well.However, the coaxially and longitudinally coextensive arrangement of thestent and graft has resulted in a cross-sectionally large assembly. Across-sectionally large graft and stent assembly can be difficult toinsert and deliver intravascularly to the damaged section of the bloodvessel and may require surgery.

[0011] The inventor herein has developed low-profile stent/graftstructures, as shown for example in U.S. Pat. No. 6,015,422, U.S. Pat.No. 6,102,918 and U.S. Pat. No. 6,168,620.

[0012] In view of the above, it is an object of the subject invention toprovide improvements in vascular stent and graft assemblies that providea small cross-section and low profile.

[0013] It is also an object of the invention to provide an endovascularstent and graft assembly that can be introduced easily into and throughthe damaged or diseased section of a blood vessel.

[0014] A further object of the subject invention is to provide a systemof endovascular stents and grafts that can be assembled intravascularlythrough damaged regions of a blood vessel.

SUMMARY OF THE INVENTION

[0015] The subject invention is directed to an endovascular graftassembly that comprises at least one tubular vascular graft and at leastone fixation device. The tubular graft and the fixation device areconnected substantially in end-to-end relationship with little or nolongitudinal overlap. In certain embodiments, the substantiallyend-to-end relationship of the tubular graft and the fixation device mayinclude a small axial space between the tubular graft and the fixationdevice. One or more connecting wires may bridge the space between theaxially align tubular graft and fixation device. The tubular graft has alength that exceeds the length of a damaged section of a blood vesselthat is being repaired by the endovascular graft assembly. The tubulargraft also has a cross-sectional size that is about 10%-30% wider thanthe cross-sectional size of the blood vessel that is being repaired. Thetubular graft preferably is formed from a synthetic material, such as amaterial formed from an ultra thin polyester fiber, or other vasculargraft materials known to those skilled in this art.

[0016] The fixation device may comprise a generally tubular stent. Oneend of the tubular stent is securely affixed to one end of the tubulargraft. The end-to-end fixation of the graft to the stent preferably iscarried out with little or no telescoping between the tubular graft andthe stent. However, a slight amount of telescoping (e.g. 0-20 mm) may berequired to ensure a secure and substantially permanent interengagement.The connection between the tubular graft and the tubular stent may beachieved by hooking, stitching, fusing or other such secure connectiontechniques. The connection need not be continuous around the peripheriesof the stent and the tubular graft. Thus, the stent and the tubulargraft merely may be connected at one location on their respective endsor at plural spaced-apart locations.

[0017] The fixation device need not be a tubular stent. Rather, thefixation device may comprise a plurality of hooks that extend from atleast one longitudinal end of the tubular graft. The hooks can beengaged with healthy sections of blood vessel on either side of ananeurysm. The fixation device may further include an annular ringaffixed to an axial end of the tubular graft, and the hooks may projectaxially from the ring. The ring functions to keep the tubular graft openduring insertion of the endovascular graft assembly into the bloodvessel.

[0018] The endovascular graft assembly further comprises an internalstent to provide radial support for the tubular graft of theendovascular graft assembly. However, unlike prior art endovasculargraft assemblies, the internal stent of the subject invention isdeployed after the end-to-end assembly of the fixation device andtubular graft have been positioned properly across the aneurysm. Theinternal stent may be a balloon expandable stent or a self-expandingstent. However, the insertion of the internal stent after the insertionof the end-to-end assembly of the fixation device and tubular graftgreatly facilitates the deployment of the entire endovascularstent/graft assembly to the proper location.

[0019] The endovascular graft assembly may further include at least onesupport that extends from the fixation device into the graft to preventthe graft from collapsing radially or axially during or afterinstallation and/or to provide radially outward support for the graft.The support may comprise at least one longitudinally extending wireextending from the fixation device substantially entirely through thegraft and then anchored at the axial end of the graft opposite thestent. The support may alternatively comprise a coil extendingsubstantially from the fixation device, through the graft and to the endof the graft opposite the fixation device. The support may be connectedto the fixation device or unitary with portions of the fixation device.

[0020] The endovascular graft assembly may comprise at least twofixation devices connected respectively to opposite ends of a tubulargraft. The endovascular graft assembly may further comprise a pluralityof tubular grafts connected respectively to opposite axial ends offixation devices. The tubular graft and tubular fixation devices neednot be all of identical cross-sectional sizes. Additionally, theassembly may comprise plural fixation devices connected axially to thelegs or branches of a bifurcated or trifurcated graft, such as a grafthaving an inverted Y-shape. Furthermore, certain components of theassembly may be assembled intravascularly and intraoperatively. Theend-to-end connection of a tubular fixation device and a tubular graftprovides advantages over a graft that is at least partly coextensivewith a tubular stent. In particular, the cross-sectional dimension ofthe preferred assembly is smaller than an assembly with the tubulargraft and tubular stent at least partly coextensive with one another,and hence insertion is easier. However, the end-to-end axial connectionof a tubular graft with a tubular fixation device has advantages thatcan be applied to a coextensive tubular graft and tubular stent. Forexample, one or more tubular grafts may be assembled preoperatively withone or more tubular stent. This assembly can include a single tubulargraft with a single tubular stent inwardly therefrom, a tubular graftwith a plurality of axially spaced tubular stents inwardly therefrom oran assembly with one or more tubular stents disposed betweenconcentrically disposed inner and outer tubular grafts. Any of thesetubular stent/graft assemblies can be connected in end-to-endrelationship with a fixation device. Such an end-to-end combinationwould not achieve the small cross-section and easy insertion of theabove reference preferred embodiment. However, the end-to-end connectionof a fixation device and an assembly with a tubular graft and one ormore tubular stents can achieve enhanced fixation and can prevent theassembly of the tubular graft and tubular stents from drifting in theblood vessel.

[0021] The tubular graft and the fixation device includes connected endsthat are connected to one another in substantially end-to-endrelationship and free ends that are not connected to one another. Thus,the free end of the tubular graft is at the end of the endovasculargraft assembly remote from the fixation device. Similarly, the free endof the fixation device is at the end of the endovascular graft assemblyremote from the tubular graft.

[0022] The endovascular graft assembly may be deployed with anintroducer sheath or other such deployment device. The introducer sheathor other such device is an elongate member that may be substantiallytubular and has a cross sectional area less than the cross sectionalarea of the blood vessel that requires repair. The introducer sheath orother such introducing device has a leading end and an opposed trailingend that may be a hub. The free end of the tubular graft is attachedreleasably to the leading end of the introducer sheath or other suchdeployment device. Additionally, the free end of the fixation device ofthe endovascular graft assembly is farther from the leading end of theintroducer sheath or other such deployment device, and hence nearer tothe trailing end the introducer sheath.

[0023] The endovascular graft assembly may be introduced into a bloodvessel that requires repair. This introduction is carried out so thatthe free end of the tubular graft leads the fixation device into theblood vessel. The tubular graft is moved through the blood vessel andslightly beyond the region of the blood vessel that requires repair. Thefixation device then is moved axially within the tubular graft andtowards the leading end of introducer sheath or other such deploymentdevice. This movement of the fixation device is carried outindependently of the tubular graft and hence causes the tubular graft tobe turned substantially inside out. More particularly, the connected endof the tubular graft begins moving axially within the tubular graft andtoward the free end of the tubular graft. Sufficient movement will causethe connected end of the tubular graft to advance axially beyond thefree end of the tubular graft. The relative positions of the free end ofthe tubular graft and the free end of the fixation device will dependupon the exact characteristic of the aneurysm or other such vascularanomaly that is being corrected. In some instances, the connected endsof the tubular graft and the fixation device will be aligned with oneanother and both will be axially beyond the free end of the tubulargraft. In other instances, the connected end of the fixation device willmove axially beyond both ends of the tubular graft. In this situation,the substantially end-to-end connection of the tubular graft and thefixation device will define a connector with a slight axial gap. In someinstances, the free end of the fixation device will be within thetubular graft. In other instances, the free ends of the fixation devicewill project axially beyond the free end of the tubular graft.

[0024] All of these embodiments simplify deployment of the endovasculargraft assembly. In this regard, the endovascular graft assembly achievesthe small cross sectional dimension due to the end-to-end connection ofthe tubular graft and the fixation device during deployment. However,unlike prior art endovascular graft assemblies, there is generally noneed for an additional deployment of an internal stent to hold thetubular graft in an expanded position. Rather, the stent of theendovascular graft assembly performs the function of the internal stent.Sutures or other connectors known to those skilled in the art mayconnect the free end of the tubular graft to the leading end of theintroducer sheath or other such deployment device. The sutures, however,may form a connection that is easily releasable. The endovascular graftassembly may include means for inverting the tubular graft or turningthe tubular graft inside.

[0025] The tubular graft may be a bifurcated graft with a single tubularconnected end joined to the connected end of the fixation device insubstantially end-to-end relationship. The bifurcated graft may furtherinclude first and second tubular legs of the bifurcated graft with firstand second free ends. This embodiment of the endovascular graft assemblymay be deployed substantially in the manner described above. Inparticular, one leg of the tubular graft may be inverted and passedinteriorly into the opposed leg. This embodiment may be deployedsubstantially in the manner of the previous embodiment. However, after afinal stage of deployment, the stent or other such fixation device willbe moved axially within the bifurcated graft to a point beyond thebifurcation. The inverted leg will then be reoriented so that thebifurcated graft assumes a generally Y-shaped configuration. As before,the endovascular graft assembly in accordance with this embodimentprovides for low profile deployment and permits the assembly to be usedwithout an additional internal stent.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026]FIG. 1 is an elevational, partly in section, view of anendovascular stent/graft assembly in accordance with a first embodimentof the invention.

[0027]FIG. 2 is an enlarged elevational view, partly in section, of aconnection between the stent and graft of the assembly in either FIG. 1.

[0028]FIG. 3 is an enlarged elevational view partly in section, similarto FIG. 2, but showing an alternate connection between the stent and thegraft.

[0029]FIGS. 4A and 4B are enlarged elevational views, partly in section,showing a further alternate connection between the stent and the graft.

[0030]FIG. 5 is an elevational view of the graft with hooks for fixationto the stent or to a blood vessel.

[0031]FIG. 6 is an elevational view similar to FIG. 5, but showing hookson the tubular stent.

[0032]FIG. 7 is an elevational view of an endovascular stent/graftassembly in accordance with a second embodiment of the invention.

[0033]FIG. 8 is a schematic illustration of the endovascular stent/graftassembly of FIG. 1 inserted into a blood vessel.

[0034]FIG. 9 is a schematic illustration of an insertion of theendovascular stent/graft assembly of FIG. 1 into the abdominal aorta.

[0035]FIG. 10 is a schematic illustration of the endovascularstent/graft assembly of FIG. 1 deployed through the right iliac arteryand then inserted into the left iliac artery.

[0036]FIG. 11 is an elevational view, partly in section of a thirdalternate endovascular stent/graft assembly.

[0037]FIG. 12 is a perspective view of a fourth embodiment of anendovascular stent/graft assembly in accordance with the subjectinvention.

[0038]FIG. 13 is a perspective view of an endovascular stent/graftassembly in accordance with a fifth embodiment of the subject invention.

[0039]FIG. 14 is a side elevational view of the endovascular stent/graftassembly of FIG. 13 with a cross-sectional variation along the length ofthe graft to accommodate cross-sectional variations of the blood vessel.

[0040]FIG. 15 is a schematic view of a modular endovascular stent/graftassembly that represents a sixth embodiment of the invention intendedprimarily for deployment into the abdominal aorta and adjacent regionsof the left and right iliac arteries.

[0041]FIG. 16 is a schematic view of a seventh embodiment of anendovascular stent/graft assembly in accordance with the invention.

[0042]FIG. 17 is a schematic view of an eighth embodiment of anendovascular stent/graft assembly in accordance with the invention.

[0043]FIG. 18 is a schematic view of a variation of the eighthembodiment.

[0044]FIG. 19 is a schematic view of a modular endovascular stent/graftassembly that represents a ninth embodiment of the invention intendedprimarily for deployment into the abdominal aorta and adjacent regionsof the left and right iliac arteries.

[0045]FIG. 20 is a schematic view of a variation of the stent/graftassembly of FIG. 19.

[0046]FIG. 21 is a schematic view of a tenth embodiment of anendovascular stent/graft assembly in accordance with the invention.

[0047]FIG. 22 is a schematic view of an eleventh embodiment of anendovascular stent/graft assembly in accordance with the invention.

[0048]FIG. 23 is a schematic view of a twelfth embodiment of anendovascular stent/graft assembly in accordance with the invention.

[0049]FIG. 24 is a schematic view of a thirteenth embodiment of anendovascular stent/graft assembly in accordance with the invention.

[0050]FIG. 25 is a schematic view of a graft in a first orientation foruse in a stent/graft assembly of a fourteenth embodiment of theinvention.

[0051]FIG. 26 is a schematic view of the graft of FIG. 25 in a secondorientation.

[0052]FIG. 27 is a schematic view of the fourteenth embodiment of theinvention during an initial phase of deployment.

[0053]FIG. 28 is a schematic view of the fourteenth embodiment at alater stage of deployment.

[0054]FIG. 29 is a schematic view of the fourteenth embodiment aftercomplete deployment.

[0055]FIG. 30 is a schematic view of the fifteenth embodiment of theinvention prior to deployment.

[0056]FIG. 31 is a schematic view of the fifteenth embodiment in anintroducer sheath.

[0057]FIG. 32 schematically illustrates the introducer sheath and thestent/graft assembly of FIG. 30 being introduced into a blood vessel.

[0058]FIG. 33 is a schematic view at a first stage of deployment of thestent/graft assembly of FIG. 30.

[0059]FIG. 34 is a schematic view at a second stage of deployment of thestent/graft assembly of FIG. 30.

[0060]FIG. 35 is a schematic view at a final stage of deployment of thestent/graft assembly of FIG. 30.

[0061]FIG. 36 is cross-sectional view taken along lines 36-36 in FIG.35.

[0062]FIG. 37 is a cross-sectional view taken along lines 37-37 in FIG.35.

[0063]FIG. 38 is a schematic view of a sixteenth embodiment that issimilar to the fifteenth embodiment but employs a corrugated graft.

[0064]FIG. 39 is a schematic view of a seventeenth embodiment showing astent/graft assembly disposed in an introducer sheath.

[0065]FIG. 40 is a schematic view of the seventeenth embodiment at aninitial stage of deployment into a blood vessel.

[0066]FIG. 41 is a schematic view similar to FIG. 40 but showing thestent/graft assembly at a second phase of deployment.

[0067]FIG. 42 is a schematic view similar to FIG. 40 but showing thestent/graft assembly at a third phase of deployment.

[0068]FIG. 43 is a schematic view similar to FIG. 40 but showing thestent/graft assembly at a fourth phase of deployment.

[0069]FIG. 44 is a cross-sectional view taken along lines 44 in FIG. 43.

[0070]FIG. 45 is a schematic view showing the stent/graft assembly ofFIG. 39 after deployment.

[0071]FIG. 46 is a schematic view of an eighteenth embodiment duringdeployment.

[0072]FIG. 47 is schematic view of the eighteenth embodiment afterdeployment.

[0073]FIG. 48 is schematic view of a graft for use in nineteenthembodiment of the invention showing the graft in an initial orientationthat corresponds to a post-deployment orientation.

[0074]FIG. 49 shows the graft of FIG. 48 in an inside out invertedorientation.

[0075]FIG. 50 is a schematic view of the inverted graft of FIG. 49 withone leg of the bifurcated graft folded into the other and with a stentconnected in substantially end-to-end relationship with the graft todefine a deployment orientation.

[0076]FIG. 51 is a schematic view of the stent/graft assembly of FIG. 50at a second stage during deployment.

[0077]FIG. 52 is a schematic view of the stent/graft assembly of FIGS.50 and 51 in a third stage of deployment.

[0078]FIG. 53 is a schematic view of the stent/graft assembly of FIGS.50-52 after complete deployment.

[0079]FIG. 54-56 are schematic views showing an alternate way ofdeploying the stent/graft assembly that is depicted in FIGS. 48-53.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0080] An endovascular stent/graft assembly in accordance with a firstembodiment of the invention is identified generally by the numeral 10 inFIG. 1. The endovascular stent/graft assembly 10 includes asubstantially tubular graft 12 having a flexible wall formed from asynthetic material, such as a polyester material that is substantiallyimpervious to fluid transmission or that becomes substantiallyimpervious after exposure to blood. The tubular graft 12 has an upstreamend 14, a downstream end 16 and a fluid passage 18 extending between theends. The endovascular stent/graft assembly 10 further comprises atubular stent 20 having an upstream end 22, a downstream end 24 and apassage 26 extending between the ends. The tubular stent 20 may be ofknown construction and may be formed from materials that are known tothose skilled in the art of treating vascular anomalies withendovascular stent/graft assemblies, such as polyethylene terepthalateand PTFE, including materials sold under the trademarks DACRON® andGORTEX®.

[0081] The terms upstream and downstream used to define the ends of thetubular graft 12 and the tubular stent 20 are employed with reference tothe direction of blood flow existing during insertion of a stent graftassembly 10. More particularly, the endovascular stent/graft assemblypreferably will be inserted into a blood vessel such that the tubularstent 20 is upstream and facing into the flow of blood. The tubulargraft 12 then will trail behind the stent relative to the direction ofinsertion of the endovascular stents/graft assembly 10 and relative tothe direction of the blood flow. This preferred orientation of theendovascular stent/graft assembly 10 will enable the much more flexibletubular graft 12 to perform much in the nature of a wind-sock that isurged into an extended condition by forces exerted by the blood flow. Areversed insertion, of this first embodiment, on the other hand, couldcause the flexible tubular graft 12 to collapse in response to the bloodflow.

[0082] As shown generally in FIG. 1 and more specifically in FIGS. 2 and3, the tubular graft 12 and the tubular stent 20 are connectedsubstantially in end-to-end axial relationship. More particularly, asshown in FIG. 2, the upstream end 14 of the tubular graft 12 is buttedagainst the downstream end 24 of the tubular stent 20 to achieve a trueend-to-end axial connection between the tubular graft 12 and the tubularstent 20. This pure axial end-to-end abutment can be achieved by fusing,suturing or other known connection means that will be appreciated bypersons skilled in this art.

[0083] The true end-to-end axial connection may be difficult to achievewith certain material employed for the tubular graft and the tubularstent. In these situations, a substantially end-to-end axial connectioncan be achieved with a slight telescoping overlap as shown schematicallyin FIG. 3. With this optional arrangement, the inner circumferentialsurface of the tubular graft 12 adjacent the upstream end 14 may betelescoped slightly over the outer circumferential surface of thetubular stent 20 adjacent the downstream end 24. Sutures, fusing orother known connections then may be employed to permanently affix theslightly overlapped ends of the tubular graft 12 and the tubular stent20.

[0084]FIGS. 2 and 3 depict substantially continuous connection betweenthe annular periphery at the upstream end of the tubular graft 12 andthe annular periphery at the downstream end 24 of the tubular stent 20.However, such a continuous connection may not be required in manysituations. Rather, one or more points of contact and affixation may besufficient between the upstream end 14 of the tubular graft 12 and thedownstream end of the tubular stent 20. As noted above, end-to-end axialconnection may comprise true end-to-end connection or a connection witha slide telescope overlap between the tubular graft 12 and the tubularstent 20, as shown in FIG. 3.

[0085] As a further alternate, substantially end-to-end axialrelationship may comprise an axial gap between the tubular graft 12 andthe tubular stent 20, as shown in FIGS. 4A and 4B. FIG. 4A shows thegeneral concept of an axial gap between the tubular graft 12 and thetubular stent 20 prior to deployment. FIG. 4B shows one optionaldeployment. The axial spacing can provide even further advantages forthe deployment and positioning of the tubular graft 12 and the tubularstent 20. In this embodiment, at least one connecting wire 15 isconnected to both the tubular graft 12 and the tubular stent 20 andbridges the gap between the axially aligned tubular graft 12 and tubularstent 20. The connecting wire 15 maintains the spaced dispositionbetween the tubular graft 12 and the tubular stent 20. In thisembodiment, as well as others, a guide wire 17 may be used to guide thestent/graft assembly 10 during deployment. With reference to FIG. 4B,the tubular stent 20 may be disposed upstream from the renal arteriesand upstream from the visceral arteries shown by broken lines in FIG. 4.The tubular graft 12 has an upstream end disposed between the aneurysmand the renal arteries. The wires 15 extend between the graft 12 and thetubular stent 20. Hence, the stent/graft assembly is anchoredefficiently in a healthy section of the aorta upstream from theaneurysm. Additionally, blood flow to and from the renal arteries andthe visceral arteries is ensured by the axial gap between the tubulargraft 12 and the stent 20. The wires 15 bridge the gap between the graft12 and the stent 20.

[0086] The endovascular stent/graft assembly 12 further comprises aninternal stent 27 that is deployed after the end-to-end connectedtubular graft 12 and tubular stent 20 are in place. The internal stent27 may be a balloon expandable stent or a self-expanding stent andfunctions to maintain tubular graft 12 in an expanded non-occludedcondition. Furthermore, the internal stent 27 maintains outercircumferential surface regions of the tubular graft 12 near theupstream and downstream ends 14 and 16 in face-to-face engagement withthe inner surface of the blood vessel upstream and downstream from theaneurysm. The insertion of the internal stent 27 after positioning thetubular graft 12 and the tubular stent 20 is considerably easier thanthe prior art endovascular grafts that simultaneously attempt to advancea coaxial arrangement of graft and stent that are longitudinallycoextensive with one another.

[0087] An alternate end-to-end connection between the tubular graft 12,as shown in FIG. 5, includes a plurality of hooks 28 woven or otherwiseincorporated into the tubular graft 12 to extend axially beyond at leastthe upstream end 14. The hooks 28 on the upstream end 14 of the tubulargraft 12 can be engaged into the circumferential surface of the bloodvessel. Thus, the hooks 28 function as a fixation device that is analternate to the tubular stent 20 shown in FIGS. 1-3. The hooks 28 canbe mounted to an annular ring (not shown) that can be affixed to theupstream end 14 of the tubular graft 12. Thus, the combination of thering and the hooks 28 may function as the fixation device. A variationof the FIG. 5 embodiment, the hooks 28 at the upstream end 14 of thetubular graft 12 can be engaged into portions of the tubular stent 20adjacent the downstream end 24. Alternatively, as shown in FIG. 6, hooks30 may extend axially beyond the downstream end 24 of the tubular stent20 for engagement with portions of the tubular graft 12 adjacent theupstream end 14.

[0088]FIG. 7 shows an endovascular stent/graft assembly 32 in accordancewith a second embodiment of the invention. The endovascular stent/graftassembly 32 includes a tubular graft 12 substantially identical to thetubular graft 12 in the embodiment of FIG. 1. The stent/graft assembly32 further includes an upstream tubular stent 20 substantially identicalto the tubular stent 20 in the embodiment of FIG. 1. However, thestent/graft assembly 32 further includes a downstream stent 34. Thedownstream stent 34 has an upstream end 36, a downstream end 38 and atubular passage 40 extending between the ends. The upstream end 36 ofthe downstream stent 34 is connected in substantially end-to-endrelationship with the downstream end 16 of the tubular graft 12 by anyof the connection arrangements depicted respectively in FIGS. 2-6. Thedownstream stent 34 can be connected to the tubular graft prior toinsertion of the stent/graft assembly 32 into the blood vessel.Alternatively, the sub-assembly of the tubular graft 12 and the upstreamstent 20 can be inserted into the blood vessel substantially as shown inFIG. 1. The downstream stent 34 then can be inserted subsequently andconnected intraoperatively to the downstream end 16 of the tubular graft12.

[0089] As noted above, and as illustrated generally in FIG. 1, theendovascular stent/graft assembly 10 is fixed into the blood vessel withthe tubular graft 12 in a downstream position relative to the tubularstent 20. This orientation, does not, however, imply a requireddirection of insertion. For example, as depicted in FIG. 8, a catheter Cis employed to insert the endovascular stent/graft assembly 10 into ablood vessel V along the direction of flow and the tubular graft 12leading the tubular stent 20. Thus, despite the slow movement of thecatheter C and the stent/graft assembly 10 through the blood vessel V inthe direction of the blood flow, the tubular graft 12 will extendaxially beyond the tubular stent 20 with a substantially wind-sockeffect as described above and as shown in FIG. 8. Alternatively, thecatheter C can be used to insert the endovascular stent/graft assembly10 in opposition to the direction of blood flow, but with the tubularstent 20 in the upstream position and leading the endovascularstent/graft assembly 10 into the direction of blood flow. Morespecifically, FIG. 9 schematically depicts the insertion of theendovascular stent/graft assembly 10 through the right iliac artery 40and into the abdominal aorta 42, with the tubular stent 20 in theupstream position relative to the tubular graft 12, and with the tubularstent 20 leading the insertion against the direction of blood flow.

[0090] In certain procedures, the stent/graft assembly may start in adirection against the flow of blood but move into a different bloodvessel to follow the flow of blood. More particularly, FIG. 10 depictsthe insertion of the stent/graft assembly 10 into the right iliac artery40 for eventual insertion into the left iliac artery 44. The initialpart of this insertion will have the endovascular stent/graft assembly10 inverted relative to the preferred and eventual orientation. Thus,the tubular graft 12 may initially be in an upstream position, andaccordingly may collapse somewhat during the initial stages of theinsertion. However, the tubular graft 12 of the stent/graft assemblywill move into the downstream position relative to the tubular stent 20as the stent/graft assembly 10 moves into the left iliac artery 44.Thus, any collapsing of the more flexible graft 12 that may haveoccurred during initial insertion through the right iliac artery 40 willbe offset by the above-described wind-sock effect as the stent/graftassembly 10 moves into the left iliac artery 44.

[0091] In certain instances, it may be desirable to provide support forthe tubular graft 12 of the stent/graft assembly 10. For example, athird embodiment of the endovascular stent/graft assembly is identifiedgenerally by the numeral 46 in FIG. 11. The endovascular stent/graftassembly 46 includes a tubular graft 12 with an upstream end 14, adownstream end 16 and a tubular passage therebetween, substantially asin the first and second embodiments. The stent/graft assembly 46 furtherincludes a tubular stent 20 having an upstream end 22, a downstream end24 and a tubular passage 26 extending between the ends. As in the firstembodiment, the upstream end 14 of the tubular graft 12 is affixed insubstantially end-to-end relationship with the downstream end 24 of thetubular stent 20. The endovascular stent/graft assembly 46 differs fromthe first embodiment by the inclusion of a single wire 48 extending fromthe tubular stent 20 axially along the tubular graft 12 and affixed tothe tubular graft 12 in proximity to downstream end 16. The wire 48ensures that the tubular graft 12 will remain substantially in anextended condition and will prevent the downstream end 16 of the tubulargraft 12 from collapsing toward the tubular stent 20. The provision ofthe wire 48 may be helpful, for example, in instances depicted in FIG.10 where an endovascular stent/graft assembly may travel in counter flowdirection with the tubular graft 12 in an upstream position relative tothe tubular stent 20. Thus, the wire 48 allows the assembly 46 to bedeployed with the tubular stent 20 downstream of the tubular graft 12when there is no upstream landing place for the tubular stent 20. Asecond internal stent, such as the internal stent 27 of FIG. 1, then isdeployed to open the tubular graft 12. In this embodiment, the wind sockeffect does not occur.

[0092] A fourth embodiment of the endovascular stent/graft assembly isidentified by the numeral 50 in FIG. 12. The endovascular stent/graftassembly 50 is a variation of the stent/graft assembly 46 of FIG. 11 inthat a plurality of wires 52 extend axially from the stent 20substantially to the downstream end 16 of the tubular graft 12 where thewires 52 are affixed to the tubular graft 12. The stent/graft assembly50 prevents axial collapsing of the tubular stent 20, substantially aswith the embodiment of FIG. 11. However, the wires 52 will furtherprovide radially support for the tubular graft 12 and will resistradially collapsing of the graft 12.

[0093] A fifth embodiment of the endovascular stent/graft assembly isidentified by the numeral 54 in FIGS. 13 and 14. The stent/graftassembly 54 is similar to the stent/graft assemblies of FIGS. 11 and 12.However, the axially aligned wires of the previous embodiment arereplaced with a coil 56. The coil 56 may be anchored to the tubularstent 20 or to the upstream end 14 of the tubular graft 12 foraffixation to the downstream end 16 of the tubular graft 12. The coil 56resists axially collapsing and will assist with axial extension inresponse to any axial collapse that does occur. Additionally, the coil56 provides greater outwardly directed radially forces on the tubulargraft 12 then either of the previous embodiments.

[0094] The endovascular stent/graft assembly 32 of FIG. 7 shows that aplurality of stents 20, 34 can be assembled with a single tubular graft12. The principles embodied in FIG. 7 can be employed further to developmore complex modular assemblies. For example, FIG. 15 shows a modularassembly for repairing vascular anomalies in the region where theabdominal aorta 42 meets the right iliac artery 40 and the left iliacartery 44. In particular, the modular endovascular stent/graft assembly58 comprises a first modular subassembly 60 with a first tubular stent62 with an upstream end 64 and an opposed downstream end 66. The firstmodular subassembly 60 further comprises a first tubular graft 68 withan upstream end 70 connected substantially in end-to-end axialrelationship with the downstream end 66 of the first stent 62. The firsttubular graft 68 further includes a downstream end 72. The first modularcomponent 60 is deployed from a right leg approach into the right iliacartery 40. The first tubular stent 62 then is advanced sufficiently intothe abdominal aorta 42 for the first tubular stent 62 to be upstream ofthe aneurysm or other vascular abnormality in the abdominal aorta 42.

[0095] The modular assembly 60 further includes a second tubular stent74 that is mounted unrestrained in the first tubular graft 68 at alocation downstream from or within the aneurysm. The first tubular graft68 further includes tubular exit 76 at a location between the secondtubular stent 74 and the downstream end 72 of the first tubular graft.The second tubular stent 74 preferably is cross-sectionally larger thanboth the exit 76 and portions of the first tubular graft 68 in proximityto the exit 70. Thus, the unrestrained second tubular stent 74 will notslip longitudinally into either the exit 76 or downstream portions ofthe first tubular graft 68.

[0096] The assembly 58 further includes a second tubular graft 78 withan upstream end 80 and a downstream end 81. The second tubular graft 78is deployed from a left leg approach into the left iliac artery 44 andis advanced through the exit 76 of the first tubular graft 68. Theupstream end 80 of the second tubular graft 78 is connectedsubstantially end-to-end with the second tubular stent 74. Internalstents then may be inserted, such as the internal stent 27 describedwith respect to the first embodiment.

[0097] A seventh embodiment of the endovascular stent/graft assembly ofthe subject invention is identified generally by the numeral 82 in FIG.16. The assembly 82 comprises first and second endovascular stent/graftsubassemblies 83 and 84. The first subassembly 83 comprises a firststent 85 and a first tubular graft 86. Similarly, the second subassembly84 comprises a second stent 87 and a second graft 88. The assembly 82further includes a generally disc-like drum secured in the abdominalaorta 42 at a location upstream of the aneurysm. The drum 90 has firstand second mounting apertures 92 and 94 through which portions of thefirst and second tubular grafts 86 and 88 extend. The extreme upstreamends of the tubular grafts 86 and 88 are secured respectively inend-to-end relationship with the downstream end of the first and secondtubular stents 85 and 87, while the downstream ends of the tubulargrafts 86 and 88 are disposed respectively in the right and left iliacarteries 40 and 44. The drum or disc 90 prevents blood from flowingaround the tubular grafts 86 and 88 and into the region of the aneurysmwhere blood pressure could cause a rupture of the aneurysm. The stents85 and 87 provide a secure mounting of the endovascular stent/graftassembly 82 relative to the aneurysm, and prevent any parts of theassembly 82 from migrating downstream due to the pressure of the bloodflow. The endovascular stent/graft assembly 82 of FIG. 16 is used incombination with internal stents, such as the internal stent 27 in FIG.1, that are introduced to the tubular grafts 86 and 88 after completeimplantation of portions of the assembly 82 depicted in FIG. 16.Additionally, the assembly 82 may be used in combination with one or twodownstream stents, or other fixation devices secured to downstream endsof the respective tubular grafts 86 and 88.

[0098] An eighth embodiment of the endovascular stent/graft assembly ofthe subject invention is identified generally by the numeral 96 in FIG.17. The stent/graft assembly 96 is designed in recognition of the factthat somewhat less than half of all patients have a neck defined in theabdominal aorta immediately upstream of the aneurysm. The neck isaligned to the aneurysm at an angle of less than 180°. Endovascularstent/graft assemblies exhibit some flexibility. Thus, a conventionalcylindrical endovascular stent/graft assembly can be biased into anoncylindrical curved shape that conforms to the shape of the neckadjacent the aneurysm. However, an initially cylindrical stent/graftassembly with a linear axis of symmetry that is biased into a curvednoncylindrical shape will exhibit internal resiliency that will tend toreturn the stent/graft assembly back to an unbiased cylindricalconfiguration.

[0099] A stent/graft assembly that initially is concentric about alinear axis and then is bent to be concentric about a curved axis willcause portions of the stent/graft assembly on the outside of the curveto circumscribe a smaller arc angle than portions of the stent/graftassembly more inwardly on the curve. As a result, portions of thecylindrical stent/graft assembly that initially are concentric about alinear axis and then are curved to be concentric about a curved axiswill be affixed less securely in healthy regions of the blood vesselupstream from the aneurysm and on the outside of the curve of thestent/graft assembly. This configuration is illustrated by the brokenline on the endovascular stent/graft assembly 96 shown in FIG. 17. Itwill be appreciated that even minor shifting of the endovascularstent/graft assembly after implantation can result in catastrophic leaksbetween the stent/graft assembly and the aneurysm.

[0100] To avoid the above-described problems, the endovascularstent/graft assembly 96 shown in FIG. 17 is preformed to be unbiased ina curved condition symmetrical about a curved axis. Thus, thestent/graft assembly 96 can be considered to define a section of torus.Additionally, the upstream end 97 is substantially perpendicular to thecurved axis of the stent/graft assembly. This requires the stent/graftassembly 96 to be longer on the outside of the curve than on the insideof the curve so that portions of the stent/graft assembly 96circumscribes substantially equal angles on both inner and outerextremes of the curved stent/graft assembly 96. The curve in theendovascular stent/graft assembly 96 can be achieved by providinglongitudinally extending fibers or filaments in the stent and/or thegraft that have a preset curve, and aligning the curve filaments, fibersor wires to be substantially parallel with one another. Alternatively,longitudinal extending filaments, fibers or wires on one side of thecurve endovascular stent/graft assembly 96 may be shorter than those onthe opposite longitudinal side. Still further, a preset unbiased curvedcan be achieved by appropriate heat treatment of an initiallycylindrical stent.

[0101] The stent/graft assembly 96 can be biased from its preset curvedor toroidal condition back into a substantially cylindrical conditionfor deployment. This biased cylindrical shape can be maintained by theintroducer that is use during deployment. The introducer is removedsubstantially in the conventional manner after proper positioning of thestent/graft assembly 96. At that time, the stent/graft assembly 96 willbe released from its biased cylindrical configuration and will return toits preset unbiased curved or toroidal configuration substantiallyconfirming to the shape imparted by the neck upstream from the aneurysm.The preceding embodiments all relate to stent/graft assemblies where thegraft is fixed in substantially end-to-end relationship with the stent.Such a configuration also is acceptable for the stent/graft assembly 96.However, the curved stent/graft assembly 96 also is effective for thosesituations where the stent and the graft are longitudinally coextensivewith one another and where the upstream and downstream ends of both thestent and the graft are at the same or similar axial positions.

[0102]FIG. 18 shows an angulated endovascular stent/graft assembly 196that is provided for situations similar to those described above withrespect to FIG. 17. The endovascular stent/graft assembly 196 includes astent 196 with an upstream end 200, a downstream end 202 and alongitudinal axis 204 extending therebetween. The upstream end 200 isaligned substantially orthogonal to the longitudinal axis 204 of thestent 198. The downstream end, however, is not perpendicular to the axis204, and hence defines a beveled end. The stent/graft assembly 196further includes a tubular graft 206 having an upstream end 208, anddownstream end 210 and an axis 212 extending between the ends. Thedownstream end 210 is aligned substantially orthogonal to the axis 212.However, the upstream end 208 is not orthogonal to the axis 212. Hence,the upstream end 208 defines a beveled end. The beveled upstream end 208of the graft 206 is connected substantially and end-to-end relationshipwith the beveled downstream end 202 of the stent 198. As in the previousembodiments, the end-to-end connection can be achieved by sutures,bonding, adhesive, welding, hooks or the like. Additionally, as with thepreceding embodiments, the substantially end-to-end connection mayinclude a small amount of overlap sufficient to achieve the connection.The end-to-end connection of the beveled ends 202 and 208 of the stent198 and the graft 206 respectively creates a bend that can more nearlyapproximate the shape of the blood vessel adjacent the angulated neckupstream of the aneurysm. This alternate embodiment provides certainpracticalities over the embodiment of FIG. 17. For example, the angle ofbend can be controlled precisely by effectively mitering the ends at anappropriate angle. Second, insertion can be easier than with astent/graft assembly that is curved along its length. In this latterregard, it will be appreciated that the graft 206 is very flexible andduring insertion will collapse and readily follow the stent 198 as thestent 198 is inserted generally along its axis 204.

[0103]FIG. 19 shows an endovascular stent/graft assembly 98 with a stent20, substantially identical to the stents 20 described and illustratedabove. More particularly, the stent 20 of the assembly 98 in FIG. 19 hasopposed upstream and downstream ends 22 and 24. The assembly 98 includesa one piece bifurcated graft 100. The graft 100 includes an upstream end102 that is fixed in substantially end-to-end axial engagement with thedownstream end 24 of the stent 20. Additionally, the graft 100 includestwo downstream legs 104 and 106 for disposition respectively in theright and left iliac arteries 40 and 44. The one piece bifurcated graft100 of FIG. 19 eliminates some of the intraoperative assembly requiredwith the modular system of FIG. 15. The bifurcated graft 100 is usedwith one or more internal stents that are deployed after insertionsubstantially as described with respect to the other embodiments.Additionally, downstream stents can be affixed to either of thedownstream legs 104 and 106.

[0104] Variations of the FIG. 19 embodiment also may be provided. Forexample, more than two legs may be provided. Furthermore the stent 20may have branches intermediate its length, and tubular grafts may beconnected in substantially end-to-end relationship with the branches ofthe stent.

[0105] An example of a variation of the FIG. 19 embodiment isillustrated in FIG. 20. In particular, FIG. 19 shows an endovascularstent/graft assembly 198 with a stent 20 identical to the stent 20described and illustrated above. The assembly 198 includes a graft 200with a tubular upstream end 202 connected to the downstream end 24 ofthe stent 20. The graft 200 also has a tubular downstream end 204 andthree tubular branches 206, 208 and 210 extending transversely fromintermediate positions along the graft 200. FIG. 20 shows theendovascular stent/graft assembly 198 deployed for treating an aneurysmof the thoracic aorta 212. The tubular branches 206, 208 and 210 extendto arteries that branch from the thoracic aorta 212, including the leftsubclavian artery 216, the left carotid artery 218 and thebrachiocephalic artery 220.

[0106] In many instances, small blood vessels will communicate withportions of the abdominal aorta that have the aneurysm. Blood deliveredby these blood vessels can increase pressure between the aneurysm andthe graft. Such pressure can lead to a rupture of the aneurysm and/ordamage to the graft. The endovascular graft assembly 108 of FIG. 21 isspecifically configured to occlude small side blood vessels that leadinto the aneurysm. More particularly, the assembly 108 includes an outerstent/graft subassembly 110 that comprises an upstream tubular stent 112and a downstream expandable graft 114. The stent 112 and graft 114 areconnected in substantially end-to-end axial alignment as described andillustrated with respect to the other embodiments herein. The downstreamgraft 114 of the outer stent/graft subassembly 110 differs from thetubular grafts described and illustrated above. More particularly, theouter graft 114 may be a synthetic fabric or a detachable balloon thathas been used in the prior art. Specifically, the outer graft 114 can beexpanded radially to conform substantially to the shape of the aneurysmand to thereby occlude the small blood vessels that lead into theaneurysm. The assembly 108 further includes an inner stent/graftsubassembly 116 that has an upstream stent 118 and a downstream tubulargraft 120. The inner subassembly 116 may be substantially identical tothe endovascular stent/graft assembly 10 described with respect to FIG.1 and other embodiments set forth above. Thus, the tubular graft 120 ofthe inner subassembly 116 is not expandable. An inner stent similar tothe inner stent 27 described and illustrated above may extend throughthe tubular graft 120. The space between the inner and outer graft 114and 120 may be filled with blood, a contrast liquid, an adhesive orwater. Variations of this embodiment may include a detachable balloonbetween the inner graft 120 and the expandable outer graft 114.Alternatively, the detachable balloon may make the separate inner graftunnecessary. Still further, the detachable balloon may make a separateinternal stent for the outer graft unnecessary.

[0107]FIG. 22 shows a stent/graft assembly 310 that incorporate featuresof the assemblies shown in FIGS. 1-4B. In particular, the stent/graftassembly 310 includes a graft 312 and a stent 320 that are connectedsubstantially in end-to-end relationship. As in the precedingembodiment, the stent 20 is intended for disposition adjacent a healthysection of the blood vessel upstream from an aneurysm. The tubular graft312 typically will extend downstream from the stent 320 across ananeurysm and into a location downstream from the aneurysm. However, manysuch aneurysms occur in the abdominal aorta slightly downstream from therenal arteries. The stent 320 often will take the form of a tubular wiremesh that normally should permit a blood flow through the tubular meshand into the renal arteries. However, the tubular mesh of the stent 320can become blocked by materials flowing in the blood. Blockage of therenal arteries can lead to kidney failure and is more likely to occurwith the wire mesh stent in place than without the wire mesh. Hence, theimplantation of the stent/graft assembly 10 of FIG. 1 in the abdominalaorta with the stent 320 aligned with the renal arteries could overcomethe problems associated with the aneurysm, but could cause kidneyproblems due to blockage of the renal arteries. The FIGS. 4A and 4Bembodiments provide one solution to that problem. FIG. 22 providesanother solution without the use of the connecting wires of FIGS. 4A and4B. In particular, the stent 320 of FIG. 22 has a downstream end 324defined by a plurality of crenulations 325 that are separated by cutouts326 that extend axially a sufficient distance to overlap the renalarteries and visceral arteries. The crenulations 325 at the downstreamend 324 of the stent 320 are affixed in substantially end-to-endrelationship with the upstream end of the tubular graft 312. The axiallyextending cutouts 326 permit unimpeded blood flow to the renal arteriesand visceral arteries.

[0108]FIG. 23 shows still a further alternative embodiment that may beadopted as an alternate to the embodiments of FIG. 4B and FIG. 22. Inparticular, the assembly 410 in FIG. 23 includes a tubular graft 412with an upstream end 414 and opposite downstream ends 416 positioned inthe iliac arteries. The assembly 410 further includes wires 420extending at least partly through the graft 412 and projecting upstreamtherefrom. Assembly 410 does not have a tubular stent comparable to thetubular stent 20 shown in FIGS. 4A and 4B. Rather, the upstream ends ofthe wires 420 are formed with hooks or barbs 422 that permit anchoringof the assembly 410 in a healthy section of a blood vessel that may beupstream from the aneurysm. The embodiment of FIG. 23 also is wellsuited for treatment of an aneurysm in the abdominal aorta. Inparticular, the upstream end 414 of the graft 412 can be positionedbetween the aneurysm and the renal arteries. The wires 420 extend tolocations in the abdominal aorta upstream from the renal arteries andupstream from the visceral arteries. Thus, as in the embodiments shownin FIGS. 4B and 22, blood flow to the renal arteries and the visceralarteries is substantially unimpeded.

[0109]FIG. 24 shows still another embodiment that may be adopted as analternate to the embodiments of FIGS. 4B, 22 and 23. In particular, theassembly 510 in FIG. 24 includes a tubular graft 512 with an upstreamend 514 and opposite downstream ends 516 positioned in the iliacarteries. The assembly 510 further includes a tubular stent 520connected to the upstream end 514 of the tubular graft 512 insubstantially end-to-end relationship. In the illustrated embodiment,the tubular stent 520 is positioned in the abdominal aorta at a locationupstream from the renal arteries. Apertures 515 are formed in portionsof the tubular graft 512 near the upstream end 514 to permit a flow ofblood to the visceral arteries and the renal arteries. However, portionsof the tubular graft 512 closer to the downstream ends 516 aresubstantially free of apertures. As illustrated in FIG. 24, theseportions of the tubular graft 512 without the apertures bridge theaneurysm.

[0110]FIGS. 25-29 show a stent/graft assembly 610 that may be similar toany of the previously described embodiments but that is orienteddifferently prior to deployment and then deployed differently. Inparticular, the assembly 610 includes a tubular graft 612 with oppositelongitudinal ends 614 and 616. The graft 612 further includes an innercircumferential surface 618 and an outer circumferential surface 619, asshown in FIG. 25. The graft 612 then is turned inside out, as shown inFIG. 26 so that the initial inner circumferential surface 618 facesoutwardly and so that the initial outer circumferential surface 619faces inwardly. In this regard, it is understood that the graft 612 isformed from thin flexible material, and the manipulation to convert thegraft 12 from the FIG. 25 orientation to the FIG. 26 orientation isroughly comparable to the manipulation carried out to fold a pair ofsocks.

[0111]FIG. 27 shows the graft 612 in the FIG. 26 orientation connectedin substantially end-to-end relationship with a stent 620 and disposedwithin a substantially conventional tubular introducer sheath 630. Moreparticularly, the stent 620 has a free end 622 and a connected end 624that is connected in substantially end-to-end relationship with the end614 of the tubular graft 612. The free end 616 of the tubular graft 612is releasably connected near the end 632 of the introducer sheath 630.The releasable connection may be achieved with sutures or other knownconnection means that would be appreciated by those skilled in this art.The introducer sheath 630 is advanced to an appropriate location in ablood vessel in a direction indicated by the arrow A in FIG. 27. Thus,the tubular graft 612 is in a leading position during this deployment.

[0112] Movement of the introducer sheath 630 in the direction A isstopped when the stent/graft assembly 610 is at an appropriate positionrelative to the aneurysm or other vascular anomaly. The stent 620 thenis advanced in the direction of the arrow A while keeping the graft 612and the introducer sheath 630 substantially stationary. This movement isillustrated schematically in FIG. 28 and begins reversing the graft 612back into the FIG. 25 orientation. This movement of the stent 620 stopsin FIG. 29 when the graft 612 has been completely reverted back to theFIG. 25 orientation. Thus, the circumferential surface 618 facesinwardly and the circumferential surface 619 faces outwardly. FIG. 29shows that the end 624 of the stent 620 is connected in substantiallyend-to-end relationship with the end 614 of the graft 612, and hencesubstantially in conforms with the preceding embodiments. The solid linedepiction of FIG. 29 shows the free ends 622 of the stent 620substantially aligned with the free end 616 of the tubular graft 612.However, the numeral 616 a shows a variation where the free end 622 ofthe stent 620 extends axially beyond the free 616 a of the graft 612.This orientation reflects the fact that there may be better directaffixation of the stent 620 to the blood vessel. The broken linedepiction in FIG. 29 shows a variation where the free end 616 b of thegraft 612 extends axially beyond the free end 622 the stent 620. Thislatter variation may require a subsequent deployment of an internalstent to support portions of the graft 612 near the free end 616 b.

[0113] The stent/graft assembly 610 illustrated in FIGS. 25-29 achievesa small cross section during deployment, as described with respect tothe previous embodiments. Additionally, the stent/graft assembly 610 ofFIGS. 25-29 can eliminate or reduce the need for internal stents, andhence substantially shortens and simplifies the surgical deployment ofthe stent/graft assembly 610.

[0114] Deployment of the stent/graft assembly 610 can be facilitated byopening the graft 612 to its full diameter prior to inverting thestent/graft assembly 610. A first approach for achieving this opening ofthe graft 612 can be achieved by employing first and second stents 620 aand 620 b fixed respectfully in end-to-end relationship to opposite ends614 and 616 of the graft 612, as shown in FIGS. 30-37. The graft 612initially is inverted, as shown in FIG. 26, so that the inner surface618 faces out. The collapsed stents 620 a and 620 b then are secured toopposite ends 614 and 616 of the graft 612 to define a stent/graftassembly 610, as shown in FIG. 30. The stent/graft assembly ispositioned in an introducer sheath 630 as shown in FIG. 31. Theintroducer sheath 630 is moved through the artery 631, as shown in FIG.32, and is positioned at an appropriate location near a diseased sectionof the artery. The stent 620 b then is advanced slightly beyond theaxial end 632 of the introducer sheath 630 and is expanded, as shown inFIG. 33, by known expansion means, such as expansion means used in knownself-expanding stents. The expansion of the stent 620 b, as shown inFIG. 33 will permit the unexpanded stent 620 a and portions of the graft612 attached thereto to be moved into and through the expanded stent 620b, as shown in FIG. 34. As a result, the graft 612 is reinverted so thatthe outer surface 619 is turned to gradually face out. The stent 620 ais moved to an appropriate position on the artery 631 spaced from thestent 620 b. The stent 620 a then is expanded into supporting engagementwith the interior surface of the artery 631, as shown in FIGS. 35-37. Inthis deployed condition, the graft 612 extends from the end of the stent620 b furthest from the stent 620 a. The graft 612 then is disposedagainst the outer circumferential surface of the stent 620 b andcontinues through the blood vessel to the end of the stent 620 afarthest from the stent 620 b.

[0115] The length of the graft 612 should be sufficient to bridge thediseased section of the artery. However, decisions regarding thedisposition of the stents 620 a and 620 b and hence the length of thegraft 612 may be made intraoperatively. To facilitate suchintraoperative decisions, a corrugated graft 612 a may be employed withthe stents 620 a and 620 b as shown in FIG. 38. This assembly of thecorrugated graft 612 a and the stents 620 a and 620 b are deployed inexactly the manner described above and shown in FIGS. 30-37. However,the corrugations in the graft 612 a permit variations in the length ofthe graft 612 a. Corrugated grafts of this type are known to thoseskilled in the art and have been used in other situations. Corrugatedgrafts are shown, for example, in published U.S. Patent Application No.US2003/0088305.

[0116] The graft 612 can be opened without the use of theabove-described second stent 620 b. More particularly, theabove-described end-to-end assembly of the graft 612 and the stent 620can be used with an expandable introducer sheath 630 a, as shown inFIGS. 39-45. An expandable introducer sheath is known in the art for useother than the use disclosed herein. A typical expandable introducersheath is shown published U.S. patent applications, includingPublication No. US2004/0082962, Publication No. 2004/0039435 andPublication No. 2004/0010280. In this embodiment, the end 616 of thegraft 612 opposite the stent 620 is temporarily and releasably connectedto the free end 632 a of an expandable introducer sheath 630 a, as shownin FIG. 39. The introducer sheath 630 a then is advanced through theartery to the selected location near the diseased section of the bloodvessel, as shown in FIG. 40. The end 632 a of the expandable introducersheath 630 then is expanded, as shown in FIG. 41, thereby causing theend 616 of the graft 612 to expand as well. The stent 620 and portionsof the graft 612 attached to the stent 620 then are advanced by a pushercatheter 640 axially through the expanded end 632 a of the introducersheath 630 a and through the opened end of the graft 612 as shown inFIG. 42. The stent 620 then is expanded (FIG. 43) and urges the graft612 out against the wall of the blood vessel, as shown in FIGS. 43 and45. The introducer sheath 630 a then is separated from the graft 612 andwithdrawn (FIG. 45).

[0117] As noted above, the substantially end-to-end affixation betweenthe stent and the graft can include an axial space between the stent andthe graft. Such a space can be applied to the embodiment of theinvention depicted in FIGS. 25-41. In this regard, the the stent/graftassembly 700 of FIG. 46 shows a graft 712 with a connected end 714 and afree end 716. The graft 712 is inverted from its pre-deploymentconfiguration so that the initial outer circumferential surface 619faces in and so that the initial inner circumferential surface 618 facesout. The stent/graft assembly 700 further includes a stent 720 with afree end 722 and a connected end 724. The connected end 724 of the stent720 is connected to the connected end 714 of the graft 720 by sutures715 or other means known to those skilled in the art that provide anaxial gap between the connected ends 714 and 724.

[0118] The stent/graft assembly 700 is deployed substantially in thesame manner as the assembly 600 described above. After properpositioning, the stent 720 is moved axially through the graft 712 andthereby reverts the graft 712 back to its original orientation with thecircumferential surface 718 facing inwardly and the circumferentialsurface 719 facing outwardly. The assembly 700 differs, however, fromthe assembly 600 in its post-deployment configuration. In particular,the axial space between the connected ends 714 and 724 results in theconnected ends 724 of the stent 720 projecting axially beyond theconnected end 714 of the graft 712. Hence, the stent 720 can be inface-to-face engagement with the inner circumferential surface of theblood vessel. Such direct affixation between the stent 720 and the bloodvessel may, in some instances, achieve better affixation than agraft-to-blood vessel affixation. The relative positions of the freeends 716 and 722 of the graft 712 and stent 720 respectively can takeany of the optional orientations depicted in FIG. 29 and described withrespect to the previous embodiment.

[0119] The aspect of the invention described with respect to FIGS. 25-46also can be applied to a bifurcated graft as illustrated in FIGS. 48-53.In particular, FIG. 43 shows a bifurcated graft 812 having a primary leg813 with a primary end 814. Additionally, the graft 812 has first andsecond bifurcated legs 815-1 and 815-2 respectively. The firstbifurcated leg 815-1 has an end 816-1 and the second bifurcated leg815-2 has an end 816-2. The graft 812, in the FIG. 48 orientation,further has an inner circumferential surface 818 and an outercircumferential surface 819.

[0120] The graft 812 then is turned inside out and into the orientationshown in FIG. 49. This is roughly comparable to the inversion describedabove with respect to FIG. 26 and is roughly comparable to turning apair of pants completely inside out. As a result, the initial innercircumferential surface 818 faces outwardly and the initial outercircumferential surface 819 faces inwardly.

[0121] The graft 812 then is manipulated further by folding andinverting the second leg 815-2 to lie substantially completely withinthe first leg 815-1. This is roughly comparable to folding the invertedpair of pants so that one leg lies completely within the other leg. Inthis configuration, the second leg 815-2 is returned temporarily to itsinitial orientation with the circumferential surface 818 facing inwardlyand with the circumferential surface 819 facing outwardly. Other partsof the bifurcated graft 812, however, retain the orientation shown inFIG. 49. FIG. 50 further shows a stent 820 with a free end 822 and aconnected end 824. The connected end 824 is joined substantially inend-to-end relationship with the primary end 814 of the graft 812.

[0122] The assembly 810 can be deployed substantially as described withrespect to the embodiment of FIGS. 25-41. More particularly, theassembly 810 is disposed in an introducer sheath by releasably affixingthe ends 816-1, 816-2 of the bifurcated legs 815-1, 815-2 near theleading end of the introducer sheath. As described above, the releasableattachment may be achieved by sutures or other known attachment means.

[0123] The assembly 810 is deployed to a proper position by theintroducer sheath. The stent 820 then is moved axially within the graft812 substantially as shown in FIG. 51. This movement of the stent 820causes a gradual inversion of the graft 812 substantially as describedwith the embodiment of FIGS. 25-29. However, in this embodiment thestent 820 moves axially within the telescoped bifurcated legs 815-1 and815-2. The advancement of the stent 820 axially within the graft 812terminates when the connected end 824 of the stent 820 is positionedproperly with respect to the connected primary end 814 of the graft 812.In the embodiment of FIG. 52 the connected ends 814 and 824 aresubstantially registered. However, the stent 820 may extend axiallybeyond the connected end 814 of the graft 812 substantially as describedwith respect to the embodiments of FIGS. 46 and 47. FIG. 52 shows thestent 820 in one possible final position relative to the primary leg 813of the bifurcated graft 812. In the FIG. 53 orientation, however, thegraft 812 has completely inverted from the orientation shown in FIG. 50.Thus, the circumferential surface 818 faces inwardly on most of thegraft and the circumferential surface 819 faces outwardly on most of thegraft. However, the second bifurcated leg 815-2 is still folded into thefirst bifurcated leg 815-1. Additionally, the second bifurcated leg815-2 has returned again its inverted orientation with thecircumferential surface 818 facing outwardly thereon and thecircumferential surface 819 facing inwardly thereon.

[0124] Deployment of the assembly 810 is completed by returning thesecond bifurcated leg 815-2 to its final position outside of the firstbifurcated leg 815-1. Thus, the circumferential surface 818 facesinwardly throughout the bifurcated graft 812 and the circumferentialsurface 819 faces outwardly on the entire bifurcated graft 812. In thisfinal deployed position, the first and second bifurcated legs 815-1 and815-2 may be in the femoral arteries of the patient.

[0125] As with the preceding embodiments, the assembly 810 provides adesirably small cross section for deployment while avoiding the need fora subsequent deployment of an internal stent on the main leg 813 of thebifurcated graft 812. Internal stents may be required in theirrespective bifurcated legs 815-1 and 815-2. However, the entire surgicalprocedure is simplified.

[0126]FIGS. 54-56 show an optional method for deploying the stent/graftassembly 810. In particular, the graft 812 is completely inverted fromthe FIG. 48 orientation into the FIG. 49 orientation and the connectedend 824 of the stent 820 is secured in substantially end-to-endrelationship with the end 814 of the graft 812. In the embodiment ofFIGS. 48-53, the second leg 815-2 is inverted and inserted into thefirst leg 815-1. In this embodiment, however, the second leg 815-2 ispermitted to collapse, but is not inserted into the first leg. The twocollapsed legs are inserted into introducer sheath 830 so that the graft812 is in a leading position relative to the stent 820. The introducersheath 830 then may be used to guide the assembly 810 into anappropriate position in the femoral artery of the ipsilateral limb. Thestent 820 then is pushed into the first bifurcated leg 815-1 of thegraft 812 and thereby turns the main leg 813 and the first bifurcatedleg 815-1 inside out. This process will loosely position the secondbifurcated leg 815-2 in an inverted orientation inside the main leg 813and/or the first bifurcated leg 815-1. The second bifurcated leg 815-2then is turned inside out and positioned properly within the femoralartery of the contrailateral limb.

[0127] The movement of the second femoral leg 815-2 can be achieved bypull suture assembly 840. In this regard, a pull suture assembly 840 isconsidered to define two sutures 841, 842 that are stitched togetheronto the second bifurcated leg 815-2 in such a manner that a pullingforce on both sutures of the pull suture assembly 840 will permit thepulling force to be transmitted to the portion of the graft 812 intowhich the sutures 841, 842 are sewn. However, a pulling force on onlyone of the sutures 841 or 842 will permit the two sutures 841, 842 toseparate from one another and from the graft. Thus, the two sutures canbe pulled simultaneously to deploy the second bifurcated leg 815-2properly. However, a single suture may then be pulled to separate thesutures from the graft 812.

[0128] While the invention has been described with respect to certainpreferred embodiments, it is apparent that various changes can be madewithout departing from the scope of the invention as defined by theappended claims. For example, for each of the optional embodiments, andvariations thereof, the substantially end-to-end stent-to-graftconnections can be pure end-to-end abutment as depicted schematically inFIG. 2 or a slightly overlapped telescoped arrangement, as shown in FIG.3. In other options, there may be a greater telescoping between thegraft and stent prior to deployment and/or during deployment. However,the graft and stent then may be extended intraoperatively into theslightly overlapped relationship depicted in FIG. 3. Embodiments of theinvention that show a curved stent/graft assembly with the stent and thegraft substantially coextensive may comprise a single tubular graft witha plurality of stents disposed substantially in end-to-end relationshipwith one another or in axially spaced relationship to one another. Atleast certain of the stents may comprise a single ring or a shortsection of a helix. In these embodiments, the graft may be inside theone or more stents, outside the one or more stents or the assembly mayhave two tubular grafts disposed respectively inside and outside the oneor more stents. Additionally, as noted above, at least a portion of agraft connected in end-to-end relationship with a stent may be connectedpreoperatively to its own stent. This later embodiment would not achievea minimum cross-sectional dimension with a correspondingly easierinsertion, but may achieve a more secure affixation than assemblies thatrely upon only a coaxially coextensive stent and graft.

[0129] The temporary connection between the graft and the introducersheath can take forms other than the sutures specifically mentionedabove. These connections may include a weak adhesive bond, a cohesion ora temporary retention between hook like structures and loops.

[0130] A tubular introducer sheath has been depicted in the figures.However, other introducing mechanisms can be employed, such as a simpleintroducer wire or a plurality of wires. Similarly, the means for movingthe contralateral leg of the bifurcated graft internally through theinverted graft can be carried out by any of a plurality of known means,including the use a second introducer sheath, an additional wire or apull thread.

[0131] The introducer sheath is depicted schematically as a continuoustube. However the end of the introducer sheath may have slits,perforations or other expandable regions to facilitate movement of thestent through the sheath.

What is claimed is:
 1. A stent/graft assembly comprising a substantiallytubular graft having opposite first and second ends, a first stentaffixed to the first end of the tubular graft and a second stent affixedto the second end of the tubular graft, portions of the tubular graftadjacent the first end surrounding said first stent, portions of thetubular graft adjacent the second end being substantially surrounded bythe second stent.
 2. A stent/graft deployment method comprising:providing a stent/graft assembly having a substantially tubular graftwith opposite first and second ends and a stent affixed to the first endof the tubular graft; mounting said stent/graft assembly into anintroducer sheath such that said second end of said tubular graft isreleasably secured in proximity to an free end of said introducersheath; guiding the free end of the introducer sheath to a selectedlocation in a blood vessel; expanding the second end of the tubulargraft circumferentially and into engagement with interior surfaceregions of said blood vessel; advancing said stent and said first end ofsaid tubular graft through the second end of the tubular graft so thatthe tubular graft is turned substantially inside out; and expanding thestent circumferentially so that the stent urges the first end of thetubular graft circumferentially into engagement with the interiorsurface regions of said blood vessel at locations spaced from theintroducer sheath.
 3. The method of claim 2, wherein the step ofproviding a stent/graft assembly comprises providing tubular graft andaffixing said stent to said graft in substantially end-to-endrelationship.
 4. The method of claim 2, wherein the step of expandingthe first end of the tubular graft includes expanding the open end ofthe introducer sheath to expand the first end of the tubular graftreleasably connected thereto.
 5. The method of claim 2, furthercomprising the step of releasing the introducer sheath from the firstend of the tubular graft.
 6. The method of claim 2, wherein the stent isa first stent and wherein the step of providing a stent/graft assemblycomprises providing a stent/graft assembly having a second stent affixedto the second end of the tubular graft, and wherein the step ofexpanding the second end of the tubular graft is carried out byexpanding the second stent.